I'm putting together an eBook with a lot of graphic content on the Kindle and need to keep the final file size below the 50Mb required to upload to KDP.

Now, the image content in the book is about 15Mb (if I add up all the file-sizes), but when Kindlegen 2.5 has build the book, the final file size is 53Mb.

Clearly, KindleGen is reprocessing the images. But what's going on here and does anyone know how to suppress the reprocessing?

Most of the files are under 63k, but some enjoy the new 127k limit. None of the images are larger than 127k.

I've tried various maximum image sizes from 525x700 down to about 520x650 (I forget the actual dimensions). I get a little but of a decrease in the file size - originally I had 75mb and got a saving after reducing the compresson rate and image dimensions.

Wondering if INCREASING the image quality and keeping the pixel size low might help - less noise in the final converted image?? ... to the photoshop batch processor.

but when Kindlegen 2.5 has build the book, the final file size is 53Mb.

Clearly, KindleGen is reprocessing the images. But what's going on here and does anyone know how to suppress the reprocessing?

A does not equal B.

The difference in final file size is mainly due to the fact that the final file contains the entire ebook in the older MOBI format ... and the entire ebook in the newer KF8 format ... and the original source files from which the ebook was built.

That's not a good idea for a publisher, because Amazon has been known to occasionally reject .mobi files generated by Calibre.

Yeeeees. I mentioned this on the KDP forums today, and had one of the (uploaded Word files until he discovered Calibre) old-timers tell me I was unequivocally WRONG about this, as he had emailed Kovid, who replied (today, apparently?):

Quote:

As far as I know, calibre generated MOBI files are still compatible with KDP.

Kovid

Thus, of course, whatever I said was, naturally WRONG WRONG WRONG, never mind that I'd checked the information with my Tech. Acct. Rep at Amazon when it was first reported back in June, having anticipated when I first saw this arise that we'd see this cropping up on the KDP fora PDQ. So I finally gave up telling people. If they want to ignore the reports, hey...I tried.

I can only assume that Kovid is making the distinction between the K7 formats and the K8, because the K7-type files, I have read, seem to be working, but anything with K8 formatting seem to be what's getting rejected. {shrug}. It's a perfectly legitimate distinction, but of course, over on the KDP forums, that distinction wouldn't be understood.

I love calibre. I use it to convert a lot of files for personal use all the time. But I wouldn't be uploading calibre produced content to KDP even if I had a pretty solid promise it was "compatible." That's not bashing calibre in any way. It just doesn't seem prudent to me to use anything other than the official tool-chain for professional publication. I'm a bit OCD in that regard.

I love calibre. I use it to convert a lot of files for personal use all the time. But I wouldn't be uploading calibre produced content to KDP even if I had a pretty solid promise it was "compatible." That's not bashing calibre in any way. It just doesn't seem prudent to me to use anything other than the official tool-chain for professional publication. I'm a bit OCD in that regard.

We keep our converted books in a Calibre Catalog. I love it for that. It has many--many--great uses. But Kovid does not claim, and never has, that it's a production tool. I, too, am a bit OCD in that regard--the right tool for the job, and all that. But people will always seek what they see as a silver bullet, the "easy way out," like magic diet pills, rather than spending a few hours learning to make a MOBI file. Hell, you can even make a passable MOBI now with WORD, for the love of heaven. Not what I'd put up as my work, mind you; but nothing wrong with it for DIY'ers.

It's not Calibre I object to, not at all. It's the Whovian "Resistance is Futile" when you try to tell people something that they don't want to hear that gets up my nose. ;-)